The invention relates to an airbag module for motor vehicles with a housing for an inflatable airbag and a gas generator.
Airbag modules of this kind serve to receive the airbag in the folded state and to inflate it by means of the gas generator in the event of an accident. The airbag modules are installed as a unit in the motor vehicle. For drivers"" side airbags, which are to be accommodated in the central region of the steering wheel, it is often desirable to have the functioning both of the airbag system as well as of the horn system of the vehicle arranged in the central region of the steering wheel. Furthermore, the air bag module is typically subject to vibrations that arise during the operation of the vehicle. Thus, it is desirable to provide an airbag module that is integrated into the vehicle in such a manner that further tasks are accomplished in addition to the protective function. Additional functions must not be affected by vibrations of the vehicle and steering column.
The object on which the invention is based is to create an airbag module that is simply constructed, that is not impaired by vehicle vibrations, and that can be used in particular as a driver""s airbag that can be integrated into a steering wheel unit.
This object is satisfied in accordance with the invention by the gas generator and the housing being movable independently of one another.
In accordance with the invention, the housing and the gas generator do not form a unit being rigidly connected to one another. This decoupling of the gas generator and the housing from one another enables the airbag module in accordance with the invention to be mounted in the motor vehicle in such a manner that vibrations arising can be specifically kept away from a certain component of the airbag module, for example from the housing. Furthermore, the total mass of the airbag module is divided up into the housing and the airbag on the one hand and into the gas generator on the other hand by the invention. The respective masses and the respective kind of coupling to the steering wheel system can be specifically tuned through the invention to additional functions which are to be assigned to the housing and/or the gas generator when installed.
In accordance with a preferred embodiment of the invention the gas generator is connected to a base element which can be secured to a steering wheel unit.
Through this the gas generator can be connected to the steering wheel unit, whereas the housing is movable relative to the steering wheel unit. The housing can be provided as the part of the horn system which is to be moved for actuating the vehicle horn, with the weight of the housing being considerably reduced as a result of the separation of the gas generator from the housing in accordance with the invention. A resilient seating of the housing at the base element, which is possibly provided, and which must be designed to be comparatively stiff in order to avoid an unintentional actuation of the vehicle horn through vibrations which are transmitted to the housing, can be designed in such a manner that the application of only a comparatively small force is required for actuating the vehicle horn. The reduced mass of the part of the airbag module to be moved thus permits the required actuation force to be reduced without at the same time increasing the possibility of unintentional actuations of the vehicle horn.
The airbag module in accordance with the invention is thus particularly well suited for use as a constituent of a combined airbag and horn system.
In accordance with a further preferred exemplary embodiment of the invention, the gas generator serves as a vibration damper.
Vibrations that, during operation of the vehicle, are transmitted for example to the steering wheel unit can be damped by the mass of the gas generator through a suitable design of the connection between the gas generator and the steering wheel unit, which is designed for the transmission of typically arising vibrations. The mass of the gas generator, which is large in comparison with the total mass of the airbag module, is thus used as a damping mass. A transmission of the vibrations to the housing of the airbag module is thereby avoided in accordance with the invention. An additional function which is possibly assigned to the housing, for example, the design as part of the actuation unit of a vehicle horn, is thus not impaired through vibrations which arise during the operation of the vehicle. This in turn simplifies the design of a seating of the housing on the steering wheel unit.
In accordance with a further preferred embodiment of the invention, at least one wall of the housing is designed as a gas inlet, with the gas generator being surrounded at least region-wise by the housing wall, which is designed as a gas inlet.
Through this a compact overall arrangement can be achieved.
In accordance with a further preferred exemplary embodiment of the invention, the gas generator, a wall of the housing which is designed as a gas inlet and at least one sealing element bound a gas inlet space.
The provision of a gas inlet space of this kind enables an optimal flowing of the gas into the housing, and thus into the airbag to be ensured, in spite of the decoupling of the gas generator from the housing.
Further preferred embodiments of the invention are set forth in the appended claims, in the description, and in the drawings.